Industry perspective: Monitoring non-target effects of anticoagulants in the UK - impacts and outcomes

Transcription

1 Vertebrate Pests Unit, School of Biological Sciences Industry perspective: Monitoring non-target effects of anticoagulants in the UK - impacts and outcomes Alan Buckle 2nd Fresenius Conference "Environmental Risk Assessment of Biocides, April 2013

2 Risk assessment and the real world Risk Assessments Real world risk monitoring Risk assessments important when we have limited real world information Improved risk management Using real world information helps improve risk management decisions 2

3 Real world information on rodenticides in the UK Warfarin introduced in 1951 Warfarin-resistance 1958 Other FGARs introduced SGARs introduced Concern about non-target impacts from 1984 Monitoring impacts from 1986 onwards UK has: 35 years experience of continuous use 30 years intensive monitoring of effects 3

4 Monitoring effects in UK UK has two independent long-term measures of environmental effects of anticoagulants. 1. Wildlife Incident Investigation Scheme (WIIS) Post-registration EFFECTS MONITORING Government officials investigate incidents in which pesticides are thought to have harmed non-target animals cides/topics/reducing-environmental-impact/wildlife 4

5 WIIS active substances WIIS Incidents by Coumpound (n = 1782) Anticoagulants most frequently involved group bromadiolone difenacoum alphachloralose brodifacoum strychnine coumatetralyl warfarin chlorophacinone flocoumafen cyanide Numbers of incidents involving bromadiolone and difenacoum reflect extensive use Some incidents are lowlevel residues, not resulting in death Analysis of WIIS data involving vertebrate pesticides 5

6 WIIS monitoring species affected Ten non-target species most common in WIIS incidents (1791 incidents) buzzard dog red kite fox cat badger barn owl badger sparrowhawk crow Analysis of WIIS data involving vertebrate pesticides Many incidents involve companion animals (dogs and cats) Among wildlife, buzzards, foxes and red kites most commonly affected With exception of red kite, incidents involving species of high conservation status (e.g. barn owl, peregrine, golden eagle) are rare n = 1791 or about 95 incidents per year 6

7 WIIS types of use WIIS Incidents by type of use (n = 1791) %of incidents are abuse and misuse 2%incidents where compounds are used correctly abuse unspecified misuse approved use other Analysis of WIIS data involving vertebrate pesticides Unspecified incidents will involve other types of use in same proportions Other category is incidents with low residue levels where pesticides were not cause of death 7

8 Monitoring effects in UK UK has two independent long-term measures of environmental effects of anticoagulants Predatory Birds Monitoring Scheme (PBMS) Bodies of birds found dead sent to Centre for Ecology and Hydrology for post mortem and residue analysis Mainly a study of background residues, but post mortem provides cause of death data 8

9 PBMS Barn Owls in the UK Percentage of barn owls with residues of anticoagulant rodenticides 30-40%barn owls carry anticoagulant residues (actually much higher) Incidence of residues increased during 1985 to 2000 Data from the Predatory Birds Monitoring Scheme W hy? More rodenticide use? Switch from FGAR to SGAR? If we knew we could mitigate against exposure better 9

10 Changes in anticoagulant use - volumes? Data from UK Pesticide Usage Surveys UseSustainability/surveys Data from UK Pesticide Usage Survey ( kg bait) ONLY partial data as some uses not included Arable farms, grassland farms, local authorities No obvious major increase in use Some switch to SGARs but insufficient to explain increase in exposure 10

11 Changes in anticoagulant use - use patterns? In 1980s tamper-resistant bait boxes (TRBBs) began to be used by PCOs Service of pro-active preventative baiting based on permanent deployment of TRBBs with SGARs This scheme was never written into product labels and was contrary to label requirements Gradually became the predominant use of SGARs by professionals Written into rules from all major agencies auditing food safety 11

12 Wild small mammals and pest rodents as prey of Barn owls in UK Prey species as a % of Barn owl diet (UK) Field vole Bank vole Wood mouse Common shrew Pigmy shrew Harvest mouse House mouse Norw ay rat Pest rodents, Norway rats and House mice, are minor items of diet If UK Barn owls are contaminated, it must mainly come through wild rodents, such as field mice and voles

13 Specific UK regulatory restriction indoor only restriction Since 1978 and 1980, bromadiolone and difenacoum permitted for use in and around buildings and outdoors From introduction in 1980 and 1987, brodifacoum and flocoumafen restricted to use indoors only Situations where the bait is placed within a building or other enclosed structure and where the target is living or feeding predominantly within that building or structure; and behind closed doors. If rodents living outside a building can move freely to where the bait is laid within the building, then products containing brodifacoum / difethialone / flocoumafen should NOT be used. 13

14 Market impacts of indoor only restriction Indoor only restriction removes capability to use products for rat control Data from UK Pesticide Usage Surveys UseSustainability/surveys Has a dramatic impact on market volumes In UK, no ability to use most potent resistancebreaking compounds in resistance management Segmentation of SGARs no longer supported by UK Competent Authority 14

15 Summary of WIIS and PBMS UK predatory birds Species Frequency (%) in WIIS incidents (n=1791) PBMS %carrying SGAR residues (n) Barn ow l (58) Kestrel (20) Red kite (18) Buzzard So what is happening in UK to populations of these birds? 15

16 Barn owl (Tyto alba) BTO long-term trend: probable decline but recent strong upturn (since 1995) BTO/JNCC/RSPB Breeding Bird Survey Historical perspective On northern limit of range in the UK very dependent on weather Dramatic decline during 20 th century causes uncertain, possibly habitat loss Conservation efforts Extensive release of captive-bred birds (600 licensed operators) Provision of nest sites by large-scale nest box schemes (>25,000) Estimate >50%current breeding in artificial nest boxes Recent strong increase in breeding pairs 16

17 UK barn owls - causes of death ( )* Cause of death number % Starvation Disease Predat ion Natural causes Road casualties Other trauma Drowned Electrocuted Accidents Poisoned (among which SGARs post-1983) (8) (1.4) Shot/trapped 11 1 Other human-related causes Unknown causes total *Newton, I., Wyllie, I., Dale, L Mortality causes in British Barn Owls (Tyto alba), based on 1,101 carcasses examined during In: Duncan J. R., Johnson D. H., Nicholls T. H., editors. Biology and conservation of owls in the northern hemisphere. Winipeg, Canada: United States Department of Agriculture. p

18 Kestrel (Falco tinnunculus) BTO/JNCC/RSPB Breeding Bird Survey BTO long-term trend: No trend, fluctuating Historical perspective Decline dues to habitat loss and impacts of OC pesticides Strong recovery by 1970s Since 1980s, populations fluctuate Breeding bird atlas: change from 1994/6 to 2007/9 Conservation efforts No concerted conservation efforts Decline in Scotland and northwest Increase in central, southern and western UK Estimated 50,000 pairs in UK 18

19 Red kite (Milvus milvus) Historical perspective Widespread persecution by game interests Virtual extinction, with tiny remnant population in Wales BTO/JNCC/RSPB Breeding Bird Survey Conservation efforts Multiple release sites of birds taken from European populations BTO long-term trend: rapid increase Dramatic increase in number of b.p b.p ,500 b.p. 19

20 Buzzard (Buteo buteo) BTO/JNCC/RSPB Breeding Bird Survey BTO long-term trend: rapid increase Historical perspective Widespread persecution by game interests Population remnant in north and west Breeding bird atlas: change from 1994/6 to 2007/9 Conservation efforts Intensive efforts to prevent shooting and poisoning Strong enforcement actions by government agencies Dramatic recovery from west to east 20

21 Summary Widespread contamination of UK wildlife with SGARs is cause of significant concern (regulators and manufacturers) 21

22 Summary Widespread contamination of UK wildlife with SGARs is cause of significant concern (regulators and manufacturers) Fatal poisoning of individual animals occurs 22

23 Summary Widespread contamination of UK wildlife with SGARs is cause of significant concern regulators and manufacturers Fatal poisoning of individual animals occurs Use of SGARs according to labels rarely found to cause fatal poisoning usual cause is abuse and misuse 23

24 Summary Widespread contamination of UK wildlife with SGARs is cause of significant concern (regulators and manufacturers) Fatal poisoning of individual animals occurs Use of SGARs according to labels rarely found to cause fatal poisoning usual cause is abuse and misuse Populations of three of the wildlife species most exposed to SGARs, barn owl, buzzard and red kite, are increasing in UK 24

25 Summary Widespread contamination of UK wildlife with SGARs is cause of significant concern (regulators and manufacturers) Fatal poisoning of individual animals occurs Use of SGARs according to labels rarely found to cause fatal poisoning s usual cause is abuse and misuse Populations of three of the wildlife species most exposed to SGARs, barn owl, buzzard and red kite, are increasing in UK SGAR mitigation measures must be targeted towards the risks they are intended to manage contamination of wildlife via wild small mammals 25